Well no, these are opinions presented as facts.
Post hoc ergo propter hoc - just because they use it doesn't mean it's good. Based on some of the music that out there I've got serious doubts about the audio perception abilities of some of these "pro's". A few points to throw out there for the sake of fun argument:
A lot of these "pro's" are behind brands for financial reasons.
A lot of people out there talk a lot of BS about how good their ear is.
Some people will rail about certain brands like Chevy vs. Ford, Apple vs. Android (Fruit v Robot), Fractal vs. Kemper, and so on and so forth.
What sounds "good" is entirely subjective. There's a lo-fi trend going on in the world today that's causing a lot of collateral damage to the zeitgeist that says what sounds good or what is acceptable insofar as that magical unicorn we call "tone" is concerned. In that reference frame, the Kemper probably sounds pretty good.
I personally have never heard a blind A/B comparison (and I think we all heard them all when the Kemper first appeared) where I thought the Kemper sounded more realistic than the Fractal (Axe-FX II at the time). To my ear it was on par with Line6 but sounded dead compared to FAS. The underlying tone might be there but I couldn't get past the muted, colorless sound of the thing and once that was established, there's really no redeeming it. That's what it will always be to me.